ESTUDYR
ANTHRO 101 EXAM 1 UPDATED EXAM WITH MOST TESTED
QUESTIONS AND ANSWERS | GRADED A+ | ASSURED SUCCESS
WITH DETAILED RATIONALES
Which three conditions are the essential ingredients for natural selection to occur?
A. Mutation, migration, genetic drift
B. Variation, inheritance, reproduction. ✓
C. Stabilizing selection, directional selection, disruptive selection
D. Adaptation, speciation, extinction
Rationale: Natural selection requires heritable variation among individuals and differential
reproductive success so that traits that improve reproduction increase in frequency.
Natural selection is best defined as:
A. Changes in a population caused only by random events
B. The tendency of organisms to become more complex over time
C. A process in which individuals with certain inherited traits tend to survive and reproduce at
higher rates than others because of those traits. ✓
D. The blending of parental traits into a uniform offspring type
Rationale: Emphasizes differential survival/reproduction tied to inherited traits (not
randomness or directed complexity).
Charles Darwin is known for:
A. Proposing inheritance of acquired traits
B. Inventing the microscope
C. Publishing the theory of evolution by natural selection in On the Origin of Species (1859).
✓
D. Showing that genes are carried on chromosomes
Rationale: Darwin formulated natural selection as the mechanism for evolution; he did not
know about genes/chromosomes.
An adaptation is:
A. Any trait that is harmful to reproduction
B. A learned behavior only
C. A trait that improves an individual’s ability to survive and reproduce. ✓
D. The same as an organism’s genotype
Rationale: Adaptations are traits favored because they increase fitness (survival/reproduction);
they can be morphological, behavioral, physiological.
,ESTUDYR
Morphology is the study of:
A. Behavior patterns in animals
B. Genetic sequences
C. Form and structure of organisms. ✓
D. Fossil dating methods
Rationale: Morphology focuses on organismal form — shapes, structures, and their
relationships.
In biology, equilibrium refers to:
A. A state where mutation rates are maximum
B. Always no change in allele frequencies forever
C. A state in which opposing forces or influences are balanced (e.g., Hardy–Weinberg
equilibrium approximates no evolutionary change). ✓
D. The physical balance of a mobile organism
Rationale: Equilibrium implies balance of forces; in population genetics it’s a theoretical state
where evolutionary forces cancel out.
Continuous variation in a trait means:
A. There are only two discrete categories
B. Traits are inherited by a single gene
C. Phenotypes show an unbroken range of values (e.g., height). ✓
D. Variation appears only after environmental change
Rationale: Continuous variation describes quantitative traits with many intermediates, typically
polygenic and environmental influence.
Which describes stabilizing selection?
A. Favors extreme phenotypes at both ends
B. Causes rapid speciation
C. Favors average individuals and reduces population variation. ✓
D. Shifts the population mean toward one extreme
Rationale: Stabilizing selection removes extremes and maintains the status quo (e.g., human
birth weight).
Which is the best one-line definition of a species in population terms?
A. Any group with similar morphology only
B. A dynamic population of interbreeding individuals reproductively isolated from other such
groups. ✓
C. All organisms living in the same habitat
D. Any organisms with the same chromosome number
, ESTUDYR
Rationale: Biological species concept emphasizes reproductive cohesion and isolation;
“dynamic” recognizes change over time.
Stasis in evolutionary terms means:
A. Rapid trait change
B. Extinction
C. Little or no evolutionary change over long periods. ✓
D. Continuous speciation
Rationale: Stasis refers to long periods during which lineages show minimal morphological
change.
Fecundity refers to:
A. Body size
B. Genetic variation
C. Fertility or reproductive capacity (number of offspring produced). ✓
D. Survival to adulthood only
Rationale: Fecundity measures potential reproductive output.
Discontinuous (discrete) variation refers to:
A. Variation shown as an unbroken gradient
B. Traits influenced by many genes only
C. Variation that falls into distinct categories (e.g., blood types). ✓
D. Variation that only occurs during development
Rationale: Discrete traits have distinct classes with little or no intermediates.
Placental mammals are characterized by:
A. Laying eggs
B. Having external gills in the embryo
C. Nourishing unborn offspring via a placenta inside the uterus. ✓
D. Having no live birth
Rationale: Placentals support embryonic development internally using a placenta (vs.
marsupials or monotremes).
Blending inheritance is the idea that:
A. Genes are discrete particles
B. Offspring inherit only maternal traits
C. Parental traits mix to form intermediate offspring traits (an incorrect model). ✓
D. Mutation produces new alleles each generation
Rationale: Blending inheritance was an early, incorrect idea; Mendelian particulate inheritance
replaced it.
ANTHRO 101 EXAM 1 UPDATED EXAM WITH MOST TESTED
QUESTIONS AND ANSWERS | GRADED A+ | ASSURED SUCCESS
WITH DETAILED RATIONALES
Which three conditions are the essential ingredients for natural selection to occur?
A. Mutation, migration, genetic drift
B. Variation, inheritance, reproduction. ✓
C. Stabilizing selection, directional selection, disruptive selection
D. Adaptation, speciation, extinction
Rationale: Natural selection requires heritable variation among individuals and differential
reproductive success so that traits that improve reproduction increase in frequency.
Natural selection is best defined as:
A. Changes in a population caused only by random events
B. The tendency of organisms to become more complex over time
C. A process in which individuals with certain inherited traits tend to survive and reproduce at
higher rates than others because of those traits. ✓
D. The blending of parental traits into a uniform offspring type
Rationale: Emphasizes differential survival/reproduction tied to inherited traits (not
randomness or directed complexity).
Charles Darwin is known for:
A. Proposing inheritance of acquired traits
B. Inventing the microscope
C. Publishing the theory of evolution by natural selection in On the Origin of Species (1859).
✓
D. Showing that genes are carried on chromosomes
Rationale: Darwin formulated natural selection as the mechanism for evolution; he did not
know about genes/chromosomes.
An adaptation is:
A. Any trait that is harmful to reproduction
B. A learned behavior only
C. A trait that improves an individual’s ability to survive and reproduce. ✓
D. The same as an organism’s genotype
Rationale: Adaptations are traits favored because they increase fitness (survival/reproduction);
they can be morphological, behavioral, physiological.
,ESTUDYR
Morphology is the study of:
A. Behavior patterns in animals
B. Genetic sequences
C. Form and structure of organisms. ✓
D. Fossil dating methods
Rationale: Morphology focuses on organismal form — shapes, structures, and their
relationships.
In biology, equilibrium refers to:
A. A state where mutation rates are maximum
B. Always no change in allele frequencies forever
C. A state in which opposing forces or influences are balanced (e.g., Hardy–Weinberg
equilibrium approximates no evolutionary change). ✓
D. The physical balance of a mobile organism
Rationale: Equilibrium implies balance of forces; in population genetics it’s a theoretical state
where evolutionary forces cancel out.
Continuous variation in a trait means:
A. There are only two discrete categories
B. Traits are inherited by a single gene
C. Phenotypes show an unbroken range of values (e.g., height). ✓
D. Variation appears only after environmental change
Rationale: Continuous variation describes quantitative traits with many intermediates, typically
polygenic and environmental influence.
Which describes stabilizing selection?
A. Favors extreme phenotypes at both ends
B. Causes rapid speciation
C. Favors average individuals and reduces population variation. ✓
D. Shifts the population mean toward one extreme
Rationale: Stabilizing selection removes extremes and maintains the status quo (e.g., human
birth weight).
Which is the best one-line definition of a species in population terms?
A. Any group with similar morphology only
B. A dynamic population of interbreeding individuals reproductively isolated from other such
groups. ✓
C. All organisms living in the same habitat
D. Any organisms with the same chromosome number
, ESTUDYR
Rationale: Biological species concept emphasizes reproductive cohesion and isolation;
“dynamic” recognizes change over time.
Stasis in evolutionary terms means:
A. Rapid trait change
B. Extinction
C. Little or no evolutionary change over long periods. ✓
D. Continuous speciation
Rationale: Stasis refers to long periods during which lineages show minimal morphological
change.
Fecundity refers to:
A. Body size
B. Genetic variation
C. Fertility or reproductive capacity (number of offspring produced). ✓
D. Survival to adulthood only
Rationale: Fecundity measures potential reproductive output.
Discontinuous (discrete) variation refers to:
A. Variation shown as an unbroken gradient
B. Traits influenced by many genes only
C. Variation that falls into distinct categories (e.g., blood types). ✓
D. Variation that only occurs during development
Rationale: Discrete traits have distinct classes with little or no intermediates.
Placental mammals are characterized by:
A. Laying eggs
B. Having external gills in the embryo
C. Nourishing unborn offspring via a placenta inside the uterus. ✓
D. Having no live birth
Rationale: Placentals support embryonic development internally using a placenta (vs.
marsupials or monotremes).
Blending inheritance is the idea that:
A. Genes are discrete particles
B. Offspring inherit only maternal traits
C. Parental traits mix to form intermediate offspring traits (an incorrect model). ✓
D. Mutation produces new alleles each generation
Rationale: Blending inheritance was an early, incorrect idea; Mendelian particulate inheritance
replaced it.
